Professor Anne Hemingway
What it is, what it does and why this can be a test for everyone. We’re dispelling the myths and explaining the benefits for natural fertility.
A hysterosalpingogram (HSG), is an X-ray to look for abnormalities in the womb, or blockages in the fallopian tubes, which may explain why a woman is unable to get pregnant or is suffering miscarriages. Sometimes we undertake the investigation in women who have had surgery to their womb or tubes to check all is well before they try to conceive.
Who should have an HSG test?
A woman will be referred for an HSG by her fertility team. The HSG, together with ultrasound (which looks at the ovaries, the lining and wall of the womb), blood tests (which check how the ovaries are working) and her partner’s sperm test, give the fertility team a picture of what is causing subfertility and informs them how best to treat the couple.
How is an HSG performed?
The examination is undertaken in the first half of the woman’s menstrual cycle, after she has stopped bleeding. She is asked not to have intercourse from the first day of the period and until after the test to ensure she is not pregnant at the time of the examination.
It is important to remember that, for these couples, the infertility journey can be a stressful time. We should recognise that and treat them with dignity, respect and empathy.
Our emphasis is to be kind, gentle and not to rush
On arrival, the woman will be asked to change into a gown and brought to the X-ray room. After taking a brief history, the procedure is fully explained, and the woman is given time for questions and is asked to give her consent to proceed. She then lies on the X-ray table in a similar position to having a smear.
A speculum is very gently inserted into the vagina. A very soft tube or catheter is then passed into the canal that leads from the cervix to the womb. A clear liquid (called ‘contrast’) is then gently passed into the womb. It contains iodine, which can be seen on X-ray images. Using an X-ray camera the doctor watches on a TV screen as the fluid passes into the womb and the tubes. Four or five pictures are taken to make a record of what is seen.
The X-ray table may be tilted, or the patient asked to roll from side to side to help the tubes to fill. Coughing and laughter are great aids to tubal filling!
What are the risks?
Risks are few and should be discussed in detail with the doctor undertaking the procedure.
Discomfort – patients’ pain thresholds vary. Some women don’t feel a thing, some find it uncomfortable a bit like period cramps. Only a very few, in our experience, find it very painful.
Infection – this is uncommon and most likely to occur in women who have had an infection before. In our practice all ladies are given a single dose of antibiotics to minimise this risk.
Reaction to fluid (contrast) – this is very unusual with modern contrast, we check beforehand if women have any significant allergies.
Radiation – radiologists work within very strict regulations regarding about the amount of radiation that can used and there are national guidelines to minimise any risk from radiation.
The benefits of an HSG
There are two types of fluid (contrast) we can use for an HSG – one is water soluble the other is oil soluble. There have been many anecdotal reports of enhanced natural pregnancy rates after an HSG. In 2017, a detailed study undertaken in the Netherlands proved conclusively that, in women under 38 with unexplained subfertility, an HSG with oil-based contrast resulted in higher ongoing pregnancy and live birth rates than an HSG with water soluble contrast.
So, in couples with unexplained infertility the HSG is not only diagnostic but may also offer them an increase chance of natural conception.